Dual roll casting machine

ABSTRACT

A twin roll casting machine that can reduce an amount of inert gas supplied. A duct is upwardly urged by cylinders to compress resilient sealing members respectively between a flange on a casting module and an upper flange on the duct and between a lower flange on the duct and a lower surface on a peripheral edge of an upper-end opening of an enclosure to maintain air-tightness of connections between the casting module and the duct and between the duct and the enclosure. A scrap box is moved upward by jacks to make a lower edge of a partition plate of an upper sealing member on the enclosure penetrate into the sealing material stored in a groove on the scrap box to maintain air-tightness of a connection between the scrap box and the enclosure.

TECHNICAL FIELD

[0001] This invention relates to a twin roll casting machine.

BACKGROUND ART

[0002]FIG. 1 shows a conventional twin roll casting machine based on aninvention disclosed in JP-8-300108A.

[0003] This twin roll casting machine comprises a casting module 3 witha pair of chilled rolls 1 adapted to continuously cast a strip 2, a pairof pinch rolls 4 for pinching the strip 2 from the chilled rolls 1 tofeed the same to a succeeding process such as rolling, an enclosure 5with an open lower end for enclosing a transfer path of the strip 2 fromthe casting module 3 to the pinch rolls 4, a scrap box 7 with anupper-end opening confronting the lower-end opening of the enclosure 5,said scrap box being vertically movable by jacks 6, and a sledding table8 and a plurality of table rolls 9 arranged within the enclosure 5.

[0004] The casting module 3 has a pair of side weirs 10 abutting on oneand the other ends of the chilled rolls 1, respectively, a sealingchamber 11 under the chilled rolls 1 for surrounding the transfer pathof the strip 2 and sealing members 12 contiguous with an upper end ofthe sealing chamber 11 to abut on outer peripheries of the chilled rolls1.

[0005] The chilled rolls 1 are horizontally arranged in parallel witheach other, a nip between the rolls being adjustable to be selectivelyincreased or decreased depending upon thickness of the strip 2 to becast.

[0006] Rolling directions and velocities of the chilled rolls 1 are setsuch that the outer peripheries of the rolls are moved from above towardthe nip at the same velocity.

[0007] The chilled rolls 1 are structured such that cooling water maypass through the rolls.

[0008] Molten metal is fed to a space defined by the chilled rolls 1 andthe side weirs 10 to form a molten metal pool 13.

[0009] Formation of the molten metal pool 13 and rotation of the rolls 1which are being cooled cause the metal to solidify on the outerperipheries of the chilled rolls 1 so that the strip 2 is delivereddownward via the nip.

[0010] The pinch rolls 4 are arranged downstream of the chilled rolls 1and adjacent to a succeeding process to which the strip 2 is to bedelivered.

[0011] An upper end of the enclosure 5 provides a sealing chamber 14into and from which a lower end of the sealing chamber 11 of the castingmodule 3 may be inserted and withdrawn.

[0012] A sealing member 15 is arranged between a vertical wall of thesealing chamber 14 and a lower vertical surface of the sealing chamber11 of the casting module 3 and is in surface contact wholly withperipheries of these sealing chambers 11 and 14.

[0013] A downstream portion of the enclosure 5 in a direction of travelof the strip 2 is provided with sealing members 16 abutting on outerperipheries of the pinch rolls 4.

[0014] A peripheral edge of the upper-end opening of the scrap box 7 isprovided with a sealing member 17 which may be in surface contact whollywith a peripheral edge of the lower-end opening of the enclosure 5 whenthe scrap box 7 is lifted up by the jacks 6.

[0015] This scrap box 7 is provided to withdraw any shape-defectivestrip 2 produced upon initial phase of a casting operation.

[0016] Inert gas (nitrogen gas) G is fed through a conduit 18 into thecasting module 3, the enclosure 5 and the scrap box 7 so as to maintaininteriors of the same in non-oxidative atmosphere for prevention of thehot strip 2 from oxidization.

[0017] The inert gas G is restrained from flowing outside by the sealingmembers 12 and 16, respectively, between the sealing chamber 11 and thechilled rolls 1 and between the enclosure 5 and the pinch rolls 4.

[0018] The sledding table 8 is adapted to take two alternative postures,one for guidance of the strip 2 from the chilled rolls 1 to the pinchrolls 4 and the other not in contact with the strip 2.

[0019] The sledding table 8 is arranged to support from below the strip2 passing via the table rolls 9 to the pinch rolls 4.

[0020] However, in the twin roll casting machine shown in FIG. 1,atmosphere temperature in the enclosure 5 may rise under the influenceof the hot molten metal pool 13, resulting in thermal deformation of thesealing chambers 11 and 14, the enclosure 5 and the scrap box 7.

[0021] This causes the sealing members 15 and 17 not to be in surfacecontact wholly with the outer periphery of the sealing chamber 11 andwholly with the peripheral edge of the lower-end opening of theenclosure 5, so that the inert gas G to be charged in the casting module3, the enclosure 5 and the scrap box 7 is allowed to flow outside andambient air flows into the enclosure 5 and the like in an amountcorresponding to that of the inert gas G having flowed outside.

[0022] Therefore, the enclosure 5 must be replenished with inert gas Gin an amount corresponding to that of the inert gas G having flowedoutside so as to prevent the strip 2 from being oxidized.

[0023] The present invention was made in view of the above and has itsobject to provide a twin roll casting machine which can reduce an amountof inert gas supplied for prevention of the strip from oxidization.

SUMMARY OF THE INVENTION

[0024] In a twin roll casting machine according to the invention, theduct is urged upward by the pushing means to compress the resilientsealing members respectively between a peripheral edge of the lower-endopening of the casting module and the upper flange and between the lowerflange and the lower surface on the peripheral edge of the upper-endopening of the enclosure; these resilient seals maintain air-tightnessof the connections between the casting module and the duct and betweenthe duct and the enclosure.

[0025] The resilient sealing members to be compressed may be hollow tobe readily in close contact with the casting module and the enclosure,which improves the air-tightness of the connections between the castingmodule and the duct and between the duct and the enclosure.

[0026] The scrap box may be moved upward by the lift means so that alower edge of the partition plate is penetrated into the sealingmaterial stored in the groove so that the air-tightness of theconnection between the scrap box and the enclosure is maintained by thelower sealing member, the sealing material and the upper sealing member.

[0027] The lower sealing member with the plural grooves and the uppersealing member with the plural partition plates may provide a multiair-tightness maintaining boundary, which improves air-tightness of theconnection between the scrap box and the enclosure.

[0028] The sealing material to be stored in the groove of the lowersealing member may be powder or granule so as to reduce wear or wastageof the sealing material.

[0029] The sealing material to be stored in the groove on the lowersealing member may be liquid so as to facilitate a charging operation ofthe sealing material into the groove.

BRIEF DESCRIPTION OF DRAWINGS

[0030]FIG. 1 is a schematic diagram showing a conventional twin rollcasting machine;

[0031]FIG. 2 is a schematic diagram of an embodiment of a twin rollcasting machine according to the invention; and

[0032]FIG. 3 is a sectional view showing a sealing structure between theenclosure and the scrap box in connection with FIG. 2.

BEST MODE FOR CARRYING OUT THE INVENTION

[0033] An embodiment of the invention will be described in conjunctionwith the drawings.

[0034]FIGS. 2 and 3 shows an embodiment of a twin roll casting machineaccording to the invention in which parts same as those in FIG. 1 arerepresented by the same reference numerals.

[0035] This twin roll casting machine comprises a duct 19 arrangedbetween a casting module 3 and an enclosure 5 to surround a strip 2 fromchilled rolls 1, an upper flange 20 contiguous with an upper-endperipheral edge of the duct 19 to extend peripherally, a lower flange 21contiguous with a lower-end peripheral edge of the duct to extendperipherally, resilient sealing members 22 and 23 mounted over uppersurfaces of these flanges 20 and 21, cylinders 24 which urge the duct 19upward, a lower sealing member 26 arranged over an outer periphery of ascrap box 7 and having peripherally extending grooves 25, sealingmaterial 27 stored in grooves 25 on the lower sealing member 26 and anupper sealing member 29 arranged over an outer periphery of theenclosure 5 and having partition plates 28 adapted to be fitted in thegrooves 25.

[0036] The sealing chamber 11, which constitutes the casting module 3,is provided with a flange 30 contiguous with a lower-end peripheral edgeof the same to extend peripherally.

[0037] A lower portion of the duct 19 is vertically movably insertedinto an opening on an upper end of the enclosure 5, and the upper flange20 precisely confronts the flange 30 of the sealing chamber 11.

[0038] Moreover, the lower flange 21 confronts a lower surface on aperipheral edge of the upper-end opening of the enclosure 5.

[0039] The resilient sealing members 22 and 23 are made fromheat-resisting material to be compressively deformable.

[0040] The upper resilient sealing member 22 is fixed to the upperflange 20 and not to the flange 30 of the sealing chamber 11 for thepurpose of making the casting module 3 displaceable upon replacement ofthe chilled rolls 1.

[0041] The lower resilient sealing member 23 may be fixed only to thelower flange 21; alternatively, it may be fixed both to the lower flange21 and to the enclosure 5.

[0042] These resilient sealing members 22 and 23 may be of solid orhollow endless shape to utilize resiliency of the material itself whenthe material is a heat-resistant high molecular compound. They may be oftelescopic bellows shape when the material is metal sustainable torepeated stress in hot atmosphere.

[0043] The cylinders 24 are arranged outside of the duct 19 such thatpiston rods 31 of the cylinders are directed upward, the piston rods 31being associated with the duct 19.

[0044] Upward movement of the piston rods 31 of the cylinders 24compresses the resilient seal members 22 and 23 respectively between theabove-mentioned flange 30 and the upper flange 20 and between the lowerflange 21 and the lower surface on the peripheral edge of the upper-endopening of the enclosure 5.

[0045] This causes the resilient sealing members 22 and 23 to maintainthe air-tightness of the connections respectively between the sealingchamber 11 of the casting module 3 and the duct 19 and between the duct19 and the enclosure 5.

[0046] In other words, even if the sealing chamber 11, the duct 19 andthe enclosure 5 are thermally deformed due to the hot atmosphere in theenclosure 5 under the influence of the hot molten metal pool 13, theinert gas G charged through the conduit 18 into the casting module 3,the enclosure 5 and the scrap box 7 is not allowed to flow outside viathe above-mentioned connections.

[0047] Downward movement of the piston rods 31 of the cylinders 24separates the resilient sealing members 22 and 23 away from the flange30 and from the lower surface on the peripheral edge of the upper-endopening of the enclosure 5, respectively.

[0048] In the case of the resilient sealing member 23 being fixed bothto the lower flange 21 and to the enclosure 5, downward movement of thepiston rods 31 causes the resilient sealing member 23 to expand.

[0049] The lower sealing member 26 is formed with the two grooves 25each of which has an open upper end and circumferentially surrounds theupper end of the scrap box 7.

[0050] The sealing material 27 used is amorphous material havingfluidity, and may be powder or granule such as sand or liquid such aswater.

[0051] In the case of the sealing material 27 used being powder orgranule such as sand, no wear or wastage occurs due to evaporation atatmosphere temperature outside of the scrap box 7, which can reducereplenishment work of the sealing material 27.

[0052] In the case of the sealing material 27 used being liquid such aswater, which is superior in fluidity to powder or granule, the grooves25 may be readily and uniformly replenished with the sealing material 27on an occasion of the sealing material 27 being reduced in amount due toattachment and detachment of the scrap box 7 to and from the enclosure5.

[0053] The partition plates 28 of the upper sealing member 29 arecontiguous with the enclosure 5 and circumferentially and doublysurround the lower end of the enclosure 5 in conformity with the grooves25.

[0054] The partition plates 28 and the grooves 25 are relativelypositioned such that the partition plates 28 are fitted into the grooves25 when the scrap box 7 just below the enclosure 5 is moved upward bythe jacks 6 and that the partition plates 28 are separated away from thegrooves 25 when the scrap box 7 is lowered by the jacks 6.

[0055] As a result, upward movement of the scrap box 7 by the jacks 6causes lower edges of the partition plates 28 to be penetrated into thesealing material 27 stored in the grooves 25 so that the lower sealingmember 26, the sealing material 27 and the upper sealing member 29maintain the air-tightness of the connection between the scrap box 7 andthe enclosure 5.

[0056] The lower sealing member 26 with the two grooves 25 and the uppersealing member 29 with the partition plates 28 fittable into therespective grooves 25 provide a multiple air-tightness maintainingboundary, improving the air-tightness of the connection between thescrap box 7 and the enclosure 5.

[0057] In other words, even if the enclosure 5, the scrap box 7 and thelike are thermally deformed due to high atmosphere temperature withinthe enclosure 5 under the influence of the hot molten metal pool 13, theinert gas G charged through the conduit 18 to the casting module 3, theenclosure 5 and the scrap box 7 is not allowed to flow outside via theabove-mentioned connection.

[0058] Thus, in a twin roll casting machine shown in FIGS. 2 and 3, theair-tightness of the connections between the casting module 3 and theduct 19, between the duct 19 and the enclosure 5 and between theenclosure 5 and the scrap box 7 are maintained to restrain the inert gasG from flowing outside, whereby the amount of inert gas G supplied forprevention of the hot strip 2 from oxidization can be reduced.

1-6: (Canceled). 7: A twin roll casting machine comprising: a castingmodule with a pair of chilled rolls adapted to continuously cast astrip; a duct that has an upper-end opening confronting a lower-endopening of the casting module and through which a strip from the chilledrolls is configured to pass downward; an enclosure that has an upper-endopening for insertion of a lower portion of the duct and through whichthe strip having passed via the duct passes toward a succeeding process;an upper flange contiguous with an upper-end peripheral edge of the ductand extending peripherally; a lower flange contiguous with a lower-endperipheral edge of the duct, extending peripherally and confronting alower surface on a peripheral edge of the upper-end opening of theenclosure; resilient sealing members circumferentially over uppersurfaces of the flanges; and pushing means for urging said duct upward.8: The twin roll casting machine according to claim 7, wherein theresilient sealing members are hollow. 9: A twin roll casting machinecomprising: a casting module with a pair of chilled rolls adapted tocontinuously cast a strip; an enclosure with an upper end contiguouswith the casting module for passage of the strip from the chilled rollstoward a succeeding process, said enclosure having a lower open end; ascrap box with an upper-end opening arranged to confront the lower-endopening of the enclosure, said scrap box being vertically movable by alift; a lower sealing member arranged circumferentially over an outerside surface of said scrap box and having a circumferentially extendinggroove; an amorphous sealing material with fluidity stored in saidgroove on the lower sealing member; and an upper sealing member arrangedcircumferentially over an outer periphery of the enclosure and having apartition plate adapted to be fitted into said groove. 10: The twin rollcasting machine according to claim 9, wherein the sealing material ispowder or granule. 11: The twin roll casting machine according to claim9, wherein the sealing material is liquid. 12: A twin roll castingmachine comprising: a casting module with a pair of chilled rollsadapted to continuously cast a strip; an enclosure with an upper endcontiguous with the casting module for passage of the strip from thechilled rolls toward a succeeding process, said enclosure having a loweropen end; a scrap box with an upper-end opening arranged to confront thelower-end opening of the enclosure, said scrap box being verticallymovable by a lift; a lower sealing member arranged circumferentiallyover an outer side surface of said scrap box and having a plurality ofcircumferentially extending grooves; an amorphous sealing material withfluidity stored in said grooves on the lower sealing member; and anupper sealing member arranged circumferentially over an outer peripheryof the enclosure and having a plurality of partition plates adapted tobe fitted into said respective grooves. 13: The twin roll castingmachine according to claim 12, wherein the sealing material is powder orgranule. 14: The twin roll casting machine according to claim 12,wherein the sealing material is liquid.